Why are Neural Networks considered Artificially Intelligent?
Why in every aspect we are now considering artificial intelligence as a neural network?


"We" aren't. It is generally due to reporting by media sources that simplify science and technology news.

The definition of AI is somewhat fluid, and also contentious at times, but in research and scientific circles it has not changed to the degree that AI=NN.

What has happened is that research into neural networks has produced some real advances in the last decade. These advances have taken research-only issues such as very basic computer vision, and made them good enough to turn into technology products that can be used in the real world on commodity hardware. 

These are game-changing technology advances, and they use neural networks internally. Research and development using neural networks is still turning out new and improved ideas, so has become a very popular area to learn.

A lot of research using neural networks is also research into AI. Aspects such as computer vision, natural language processing, control of autonomous agents are generally considered parts of AI. This has been simplified in reporting, and used by hyped-up marketing campaigns to label pretty much any product with a NN in it as "Artificial Intelligence". When often it is more correctly statistics or Data Science. Data Science is another term which has been somewhat abused by media and technology companies - the main difference between use of AI and Data Science is that Data Science was a new term, so did not clash with pre-existing uses of it.

The rest of AI as a subject and area of study has not gone away. Some of it may well use neural networks as part of a toolkit to build or study things. But not all of it, and even with the use of NNs, the AI part is not necessarily the neural network.